Researchers for the Institute for Law and Economics have released a new paper that draws a correlation between mobile phone adoption and a dramatic drop in crime in the 1990s, especially instances of rape and assault. In the paper, Mobile Phones and Crime Deterrence: An Underappreciated Link, authors University of Pennsylvania Law School professor Jonathan Klick, Penn criminology professor John MacDonald, and George Mason University professor Thomas Stratmann speculate that the ability of mobile phones to allow victims to more quickly report crimes acts as a deterrent for criminals, who faced more risk in the 1990s as mobile technology became more widespread. "Mobile phones allow for quicker reporting of crimes, and, in some cases, real time communication of details about the crime and the criminal," Klick and his colleagues write. "The presence of mobile phones increases the likelihood of punishment along a number of different margins."

The researchers don't claim to offer a causal connection, and point out that "mobile phone data availability precludes us from directly investigating this link." But they say there is a correlation between mobile phone adoption and reduced crime; "although the empirical analysis doesn't prove cause and effect, it demonstrates that more mobile phones in a state is strongly correlated with reduced violent crime measures." To reach their conclusion, the authors examined mobile phone adoption in regional markets and compared it primarily with FBI Uniform Crime Report statistics on rape and aggravated assault.

So what's that mean in 2012? Extending the researchers' rationale for the drop in crime to this decade, it would seem that the effects of mobile phones on crime are potentially much stronger; in the 1990s, citizens were not carrying around sophisticated smartphones with video recording capabilities, high-resolution camera sensors, and location-aware capabilities. The researchers write that because cell phone adoption appears to be lowered by crime, "there may be relatively cheap alternatives to putting cops on the street to fight crime" — which sounds like a great idea, so long as the police don't see it as unwelcome competition.